Bi-directional power over ethernet for digital building applications

ABSTRACT

In one or more embodiments, a system includes a plurality of network devices comprising a plurality of ports, a power bus connecting the network devices, wherein power is shared between the network devices over the power bus, and a controller for identifying available power and allocating power to the ports. The ports include a plurality of PSE (Power Sourcing Equipment) PoE (Power over Ethernet) ports each operable to transmit power to a device connected to one of the PSE PoE ports, a plurality of PD (Powered Device) PoE ports each operable to receive power from a device connected to one of the PD PoE ports, and a plurality of bi-directional PoE ports each configurable to operate as a PSE PoE port to transmit power to a device connected to one of the bi-directional PoE ports or as a PD PoE port to receive power from the connected device.

STATEMENT OF RELATED APPLICATIONS

The present application claims priority from U.S. ProvisionalApplication Nos. 63/053,500 entitled BI-DIRECTIONAL POWER OVER ETHERNET,filed on Jul. 17, 2020 and 63/070,110 entitled BI-DIRECTIONAL POWER OVERETHERNET FOR INTEGRATED DIGITAL BUILDING, filed on Aug. 25, 2020. Thecontents of these provisional applications are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The present disclosure relates generally to Power over Ethernet (PoE),and more particularly, to bi-directional PoE.

BACKGROUND

In applications such as digital building system applications, there is aneed for PoE devices to connect to power devices such as solar andbattery devices, which require additional capabilities of PoE systemsthat are not currently provided by conventional PoE systems.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an example of an integrated digital building systemin which the embodiments described herein may be implemented, inaccordance with one embodiment.

FIG. 2 illustrates a bi-directional PoE system in accordance with oneembodiment.

FIG. 3 illustrates another example of the bi-directional PoE system, inaccordance with one embodiment.

FIG. 4 illustrates the bi-directional PoE system with a plurality ofswitches coupled through a common shared power bus, in accordance withone embodiment.

FIG. 5 is a block diagram of a directional power control system of thebi-directional PoE system, in accordance with one embodiment.

FIG. 6 is a block diagram of a bi-directional PoE switch, in accordancewith one embodiment.

FIG. 7 is a block diagram illustrating single pair multi-dropbi-directional PoE, in accordance with one embodiment.

FIG. 8 is a block diagram of a powered device in FIG. 7 , in accordancewith one embodiment.

FIG. 9 is a block diagram illustrating voltage conditioners atbi-directional PoE ports of a switch, in accordance with one embodiment.

FIG. 10 is an electrical schematic of a powered device (PD) circuit forthe bi-directional PoE port, in accordance with one embodiment.

FIG. 11 is an electrical schematic of a power sourcing equipment (PSE)circuit for the bi-directional PoE port, in accordance with oneembodiment.

FIG. 12 is a block diagram depicting an example of a network device inwhich the embodiments described herein may be implemented.

FIG. 13 is a flowchart illustrating a process for role reversal from PSEto PD, in accordance with one embodiment.

FIG. 14 is a flowchart illustrating a process for role reversal from PDto PSE, in accordance with one embodiment.

FIG. 15 is a power profile graph illustrating available power fromsolar, battery, and utility power sources over time.

FIG. 16 illustrates an example in which utility power is available forport use with battery and solar power reserved for port use or to pushinto utility power.

FIG. 17 illustrates an example in which utility and solar power areavailable for port use and the battery power is reserved for backup.

FIG. 18 illustrates an example of dynamic application of the utility,solar, and battery power.

FIG. 19 illustrates an example using only solar and battery power.

FIG. 20 is a flowchart illustrating an overview of a process foridentifying available power and allocating power, in accordance with oneembodiment.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Overview

In one embodiment, a system generally comprises a plurality of networkdevices comprising a plurality of ports, a power bus connecting thenetwork devices, wherein power is shared between the network devicesover the power bus, and a controller for identifying available power andallocating power to the ports. The ports include a plurality of PSE(Power Sourcing Equipment) PoE (Power over Ethernet) ports, PD (PoweredDevice) PoE ports, and bi-directional PoE ports. The PSE PoE port isoperable to transmit power to a device connected to the PSE PoE port.The PD PoE port is operable to receive power from a device connected tothe PD PoE port. The bi-directional PoE port is configurable to operateas a PSE PoE port to transmit power to a device connected to thebi-directional PoE port or as a PD PoE port to receive power from theconnected device.

In one embodiment, an apparatus generally comprises a plurality ofbi-directional PoE ports each configurable to operate as a PSE PoE portto transmit power to a device connected to one of the bi-directional PoEports or as a PD PoE port to receive power from the connected device, apower supply unit, and a fault managed power module for receiving faultmanaged power on an Ethernet cable, converting the fault managed powerto a power supply input power, and transmitting the power supply inputpower to the power supply unit.

In one embodiment, a method generally comprises identifying availablepower from a plurality of power sources comprising a utility powersource, a solar power source, and a battery power source, identifyingactive ports in a bi-directional Power over Ethernet (PoE) system, andallocating power from one or more of the power sources to power theactive ports.

In yet another embodiment, a system generally comprises a plurality ofenergy resource devices, a network device comprising a plurality of PDPoE ports operable to receive power from the energy resource devicesconnected to the PD PoE ports, and a power bus for receiving power fromthe network device and transmitting power to at least one other networkdevice comprising a plurality of PSE (Power Sourcing Equipment) PoEports for transmitting power to powered devices.

Further understanding of the features and advantages of the embodimentsdescribed herein may be realized by reference to the remaining portionsof the specification and the attached drawings.

Example Embodiments

The following description is presented to enable one of ordinary skillin the art to make and use the embodiments. Descriptions of specificembodiments and applications are provided only as examples, and variousmodifications will be readily apparent to those skilled in the art. Thegeneral principles described herein may be applied to other applicationswithout departing from the scope of the embodiments. Thus, theembodiments are not to be limited to those shown, but are to be accordedthe widest scope consistent with the principles and features describedherein. For purpose of clarity, details relating to technical materialthat is known in the technical fields related to the embodiments havenot been described in detail.

New energy systems allow for low cost solar energy to power buildingsand may also incorporate battery power distribution systems. Power overEthernet (PoE) allows for communications and power distribution toelectrically powered components and systems throughout the building,including for example, lights, blinds, emergency systems, buildingoperational systems, and other powered components and systems.Conventional PoE systems provide point-to-point PSE (Power SourcingEquipment) to PD (Powered Device) power distribution systems. Inconventional systems, the PSE powering system behind a network port onlyoperates in one direction, thus limiting capabilities within the powerdistributions system.

Embodiments described herein provide a bi-directional PoE system thatallows for PoE PSE to PD port negotiation or PoE PD to PSE portnegotiation. The bi-directional PoE system may be used, for example, toallow PoE devices to connect to solar and battery devices while alsoproviding communications on the same wires. Bi-directional PoE allows aPSE to negotiate to a PD or for a PD to negotiate to a PSE to sourcepower to an attached network device and share power with otherapplications.

One or more embodiments described herein provide a system, apparatus,method, or logic implementing bi-directional PoE to support multipleports of received power or sourced power. The system may be deployed,for example, in a digital building to support integrated digitalbuilding applications. The bi-directional PoE system provides a powerdelivery system in which one or more ports may identify a powerdirection (transmitting or receiving) based on a state of power flow.Each port may independently operate as a PSE to deliver (transmit) poweror as a PD to receive power. This allows for any combination of portstransmitting power or receiving power. As described in detail below, thebi-directional PoE system may include a bi-directional PoE circuit foreach port to be used as a PSE or PD. One or more embodiments allowdevices such as solar devices or other power sourcing devices tocontribute to a PoE power load in an environmentally responsive manner.One or more embodiments provide a bi-directional PoE system thatmaintains compatibility with existing IEEE (Institute of Electrical andElectronics Engineer) 802.3 standards.

Referring now to the drawings, and first to FIG. 1 , an example of anadvanced integrated digital building system in which the embodimentsdescribed herein may be implemented is shown, in accordance with oneembodiment. In this example, a building 10 includes solar panels 11 in asolar roof system. The building 10 may also include energy resourcesother than solar, such as a wind power system, for example. The solarpanels 11 are in communication with a power distribution system 14. Thepower distribution system 14 may receive utility power, as shown in FIG.1 . The reusable energy sources may reduce the need for utility powerand eliminate the need for a generator or central battery system. In oneor more embodiments, power from reusable power sources may also bepushed back into the utility power. The power distribution system 14 isoperable to transmit power (or transmit and receive bi-directionalpower) to a bi-directional PoE system 15.

The building 10 may be configured with one or more antennas 12 (e.g., 5Gantenna) coupled to a backhaul system 13 (e.g., defining a backhaulantenna). In one or more embodiments, the power distribution system 14is in communication with the backhaul system 13 for distributing dataalong with the power to the bi-directional PoE system 15. The data mayalso be transmitted directly between the backhaul system 13 and thebi-directional PoE system. It is to be understood that data may also bereceived by means other than the antenna 12.

In one or more embodiments, the power distribution system 14 comprisesan FMP (Fault Managed Power)/ESP (Extended Safe Power) distributionsystem that is configured to transmit and receive power or power anddata. In one or more embodiments, the power distribution system 14 maybe configured for Power over Ethernet (PoE) (e.g., conventional PoE orPoE+ at a power level <100 watts (W), at a voltage level <57 volts (V),according to IEEE 802.3af, IEEE 802.3at, or IEEE 802.3bt), Power overFiber (PoF), advanced power over data, FMP, or any other power overcommunications system in accordance with current or future standards,which may be used to pass electrical power along with data to allow asingle cable to provide both data connectivity and electrical power tonetwork devices such as switches, routers, wireless access points, andmany other network devices.

The term “Fault Managed Power” (FMP) (also referred to as Extended SafePower (ESP)) as used herein refers to high power (e.g., >100 W), highvoltage (e.g., ≥56V) operation with pulse power delivered on one or morewires or wire pairs. In one or more embodiments, FMP includes faultdetection (e.g., fault detection at initialization and between highvoltage pulses) and pulse synchronization between power sourcingequipment (PSE) and a powered device (PD). The power may be transmittedwith communications (e.g., bi-directional communications) or withoutcommunications.

The term “pulse power” (also referred to as “pulsed power”) as usedherein refers to power that is delivered in a sequence of pulses(alternating low direct current voltage state and high direct currentvoltage state) in which the voltage varies between a very small voltage(e.g., close to 0V, 3V) during a pulse-off interval and a larger voltage(e.g., >12V, >24V) during a pulse-on interval. In one or moreembodiments, the FMP (or ESP) provides high power (e.g., ≥100 W) at ahigh voltage (e.g., ≥56V). High voltage pulse power (e.g., ≥56 VDC, ≥60VDC, ≥300 VDC, ˜108 VDC, ˜380 VDC) may be transmitted from powersourcing equipment to a powered device for use in powering the powereddevice, as described, for example, in U.S. patent application Ser. No.16/671,508 (“Initialization and Synchronization for Pulse Power in aNetwork System”), filed Nov. 1, 2019, which is incorporated herein byreference in its entirety. Pulse power transmission may be throughcables, transmission lines, bus bars, backplanes, PCBs (Printed CircuitBoards), and power distribution systems, for example. It is to beunderstood that the power and voltage levels described herein are onlyexamples and other levels may be used.

In one or more embodiments, FMP may comprise pulse power transmitted inmultiple phases in a multi-phase pulse power system with pulses offsetfrom one another between wires or wire pairs to provide continuouspower. One or more embodiments may, for example, use multi-phase pulsepower to achieve less loss, with continuous uninterrupted power withoverlapping phase pulses to a powered device, as described in U.S.patent application Ser. No. 16/380,954 (“Multiple Phase Pulse Power in aNetwork Communications System”), filed Apr. 10, 2019, which isincorporated herein by reference in its entirety. In one or moreembodiments, FMP may refer to a combination of ESP (single-phase ormulti-phase DC pulse power) and PoE or a power system operable to switchbetween ESP and PoE.

The power distribution system 14 may comprise, for example, a router,switch, or other network device operable to receive power (e.g., utilitypower, solar power, battery power, wind power) and data (e.g., Ethernet)and transmit power and data to the bi-directional PoE system 15.Integration and control of power from the different power sources may beperformed, for example, as described in U.S. patent application Ser. No.16/746,500 (“Method and System for Integration and Control of Power forConsumer Power Circuits”), filed Jan. 17, 2020, which is incorporatedherein by reference in its entirety. As previously described, the powerand data may be transmitted as PoE, FMP, ESP, or transmitted using anyother suitable power over communications system. In one or moreembodiments, the power distribution system 14 transmits bi-directionalpower and data to the bi-directional PoE system 15. In one or moreembodiments, the power distribution system 14 only receives andtransmits power (or bi-directional power). As described in detail below,the bi-directional PoE system 15 may comprise one or more switches,routers, or other network devices comprising a plurality of ports with abi-directional PoE circuit for each port to be operated as a PSE or PD.The bi-directional PoE system may also include one or more networkdevices with one or more FMP ports or one or more conventional networkdevices with only PSE or PD ports.

As shown in FIG. 1 , the bi-directional PoE system is connected to anynumber of powered devices, power sourcing equipment, and bi-directionalPoE devices that may operate as PDs or PSEs. In the example shown inFIG. 1 , the digital building 10 includes a plurality of APs (AccessPoints) 16 mounted within the building or external to the building,solar operated blinds 17 a, solar films 17 b (with photovoltaic cells),LED (Light Emitting Diode) lighting 18, and one or more rechargeablebatteries 19. The bi-directional PoE system 15 may also be operable topower one or more emergency systems 25. The APs 16 may be incommunication with any number of network devices 20 (e.g., computer,laptop, tablet, mobile device, phone, and the like) via Wi-Fi.

In the example shown in FIG. 1 , the building includes an outside breakarea with a local charging station 21 (network device) operable toprovide local Wi-Fi and charging to a defined area. The charging station21 may be a mini bi-directional PSE/PD device powered withbi-directional PoE from the bi-directional PoE system 15 or powered withFMP from the power distribution system 14. The charging station 21 maybe configured for use in small spaces such as a break area (inside oroutside) covering only a designated location. The charging station 21may include, for example, one or more USB (Universal Serial Bus) ports22, a solar panel 23 a, local battery 23 b, and antenna 24. The chargingstation 21 may combine, for example, light versions of PoE, Wi-Fi,hardwire, charging, battery capability, solar charging, or anycombination thereof. The charging station 21 may also be a stand-alonesystem with the solar panel 23 a and battery 23 b providing power to thecharging station 21 and no bi-directional power input, to support asmall number of wireless devices (e.g., one-three laptops) for aspecified period of time (e.g., two hours).

It is to be understood that the digital building and integratedapplications shown in FIG. 1 is only an example, and the system mayinclude any number or type of building applications (e.g., light andtemperature control, video surveillance, emergency systems), digitalnetwork architecture (switching, routing, security), endpoint devices(e.g., sensors (lighting, environmental), IoT (Internet of Things)devices, access points, LED lighting, HVAC (Heating, Ventilation, andAir Conditioning) controller, security devices, video cameras, accesscontrol systems, conferencing systems, fire and safety systems), orpower sources (e.g., solar, wind, battery, utility).

FIG. 2 illustrates a bi-directional PoE system, in accordance with oneembodiment. A bi-directional PoE network device (e.g., switch) 26comprises a plurality of bi-directional PoE ports 28. The ports 28 areconnected to a plurality of endpoint devices 30, 32 via Ethernet cables29. The network device 26 may be configured to transmit PoE to anynumber or type of powered devices 30 (e.g., window blinds, roomlighting, television, HVAC controls, mini-bar, charging station, and thelike).

One or more of the ports 28 may be coupled to an endpoint deviceoperable as a PD or PSE based on available free power to send back intothe bi-directional PoE system. As shown in the example of FIG. 2 , theendpoint device comprises an energy resource device 32 (i.e., powersource operable to generate power local to the endpoint device andprovide the power to circuitry at the endpoint device). The energyresource device (local power source) 32 may include, for example, arechargeable battery, photovoltaic device (e.g., solar capableblind/window system, solar panel or film), or other renewable powersource or utility power source (AC power source). The energy resourcedevice 32 may operate as a PSE or PD based on available free power tosend back into the power system. If the energy resource device hasexcess power available after powering the local circuits in the endpointdevice, the energy resource device may also provide the excess power tothe network device 26 over Ethernet cable 29. The port 28 switchesbetween operation as a PSE port or PD port based on operating state ofthe energy resource device 32. As described in detail below, each of thebi-directional ports 28 and one or more ports at the endpoint devices 32may be configurable as responsive to an enable signal to operate aseither a PSE port to source power or as a PD port to receive power.Coordination between role reversal at connected ports is described belowwith respect to FIGS. 13 and 14 .

The network device 26 may include any number of PSUs (Power SupplyUnits) 34. The PSU 34 may be a removable module (field replaceable,hot-swappable device) that is received in an opening at the rear of thechassis (or other location) and configured to provide power (e.g., 48VDC, 54 VDC, or other regulated voltage) to the network device 26. Oneor more of the PSUs 34 may receive utility power or power from an UPS(Uninterruptible Power Source) at a plug 36. As shown in the example ofFIG. 2 , one of the PSUs 34 is bi-directionally coupled to a batterysystem (e.g., DC battery system, portable power system, wall mountedpower system) 38. The rechargeable battery 38 is operable to sourcepower and be charged by excess system power from the network device 26.

It is to be understood that the switch 26 shown in FIG. 2 is only anexample of a device that may be used to implement the embodimentsdescribed herein and that other types of devices (e.g., router,switch/router, or other network device) with any number of ports may beused. Also, any number of the ports may be configured for bi-directionalPoE (both PD and PSE operation), PD operation, PSE operation, or FMPoperation at one or more power levels. For example, the system may beconfigured as a 90 watt system with bi-directional PoE or abi-directional 350 watt PoE system and may be powered by an FMP powersystem with bi-directional FMP, as described below.

FIG. 3 illustrates a bi-directional PoE system utilizing FMP (alsoreferred to as FMP/ESP). In one or more embodiments, an apparatus(network device, switch) 27 comprises a plurality of bi-directional PoEports 28 each configurable to operate as a PSE PoE port to transmitpower to a device 32 connected to one of the bi-directional PoE ports oras a PD PoE port to receive power from the connected device, the powersupply unit 34, and a fault managed power module 43 for receiving faultmanaged power on an Ethernet cable 44 a, converting the fault managedpower to a power supply input power, and transmitting the power supplyinput power to the power supply unit.

The network device 27 may also comprise one or more FMP ports (e.g., FMPTX 42 b as shown in FIG. 3 , FMP TX/RX port, FMP RX port). The FMP TXport 42 b may, for example, transmit FMP over cable 44 b to one or morenetwork devices or power distribution system 31 (e.g., provide power toanother network device or powered device). As described below withrespect to FIG. 4 , the FMP TX port 42 b may be used in a bi-directionalPoE system with multiple energy resource devices to add excess powerback into a utility power source (e.g., through the power distributionsystem 14 of FIG. 1 ).

As shown in FIG. 3 an FMP bi-directional device 40 may be interposedbetween the DC battery system 38 and the bi-directional PoE switch 27 toconvert the DC battery power to FMP. The switch 27 may use excess PoEpower to push back into the FMP device 40. The battery system 38includes a bi-directional connection with the FMP device 40 so that itcan both source power or be charged by excess system power. In theexample shown in FIG. 3 , the FMP bi-directional device 40 comprises FMPtransmitter/receiver (FMP TX/RX) ports 42 a, FMP transmitter (FMP TX)ports 42 b, and FMP receiver (FMP RX) ports 42 c. It is to be understoodthat the FMP device 40 may include any number of ports configured as atransmitter/receiver, transmitter, or receiver.

The FMP device 40 has a bi-directional connection (cable 44 a) to theFMP module 43 (also referred to as a power receiver, FMP receiver, orpower adapter). The fault managed power module 43 is configured toreceive fault managed power on the Ethernet cable 44 a, convert thefault managed power to a power supply input power, and transmit the PSUinput power to the power supply unit 34. The bi-directional PoE switch27 may comprise one or more PSUs 34 (two shown in FIG. 3 ) with one ormore power adapters 43 aligned for connection with the PSUs (one adaptershown in FIG. 3 ). The FMP module 43 is operable to convert the FMP to astandard power supply input power (e.g., 240 VAC, 240 VDC, 380 VDC, orother standard PSU input power). The cable 44 a may comprise four-paircommunications cabling, Single Pair Ethernet (SPE), or any other cablecomprising one or more wire pairs. Single-phase or multi-phase pulsepower input may be provided to the FMP module 43 on the cable 44 a. TheFMP module 43 may comprise, for example, a power adapter as described inU.S. patent application Ser. No. 16/912,563 (“Power Adapter for PowerSupply Unit”), filed Jun. 25, 2020, which is incorporated herein byreference in its entirety.

FIG. 4 illustrates an example of a bi-directional PoE system comprisinga plurality of network devices (e.g., switch, router, switch/router) 45,46, 48 comprising a plurality of ports 52 a, 52 b, 52 c, 52 d, a powerbus 49 connecting the network devices, with power shared between thenetwork devices over the power bus, and a controller (system powercontroller) 47 for identifying available power and allocating power tothe ports. In one or more embodiments, a system comprises a plurality ofenergy resource devices (e.g., battery/energy storage system 53, PV(photovoltaic) device 54), the network device 46, 48 comprising aplurality of PD PoE ports operable to receive power from the energyresource devices connected to the PD PoE ports, and the power bus 49receiving power from the network device and coupled to at least oneother network device 45 comprising a plurality of PSE PoE ports fortransmitting power to powered devices 51.

In one example, the power bus 49 is configured for transmitting power ina voltage range of 54 VDC (Volts Direct Current) to 60 VDC. The powerbus 49 may be configured to transmit PoE (power and data) at anysuitable voltage level. As shown in the bi-directional PoE system ofFIG. 4 , the controller 47 is located at one of the network devices. Thecontroller may also be located at a management device coupled to thepower bus or may be a distributed control system located at one or moreof the network devices. The plurality of ports comprise a plurality ofPSE PoE ports 52 b each operable to transmit power to a powered device51 (e.g., lighting, IoT device, or other PD) connected to one of the PSEPoE ports, a plurality of PD PoE ports 52 c each operable to receivepower from a device 54 connected to one of the PD PoE ports, and aplurality of bi-directional PoE ports 52 a, each configurable to operateas a PSE PoE port to transmit power to a device 53 (e.g., rechargeablebattery, energy storage system, or other storage device) 53 connected toone of the bi-directional PoE ports or as a PD PoE port to receive powerfrom the connected device. Each network device 45, 46, 48 may includeonly one type of port (e.g., only PD ports, only PSE ports, or onlybi-directional ports) or any combination of ports. The ports may supportall twisted pair speed types.

In the example shown in FIG. 4 , three network devices 45, 46, 48 arecoupled together over the common shared power bus 49. A first networkdevice 45 (top unit in FIG. 4 ) is shown with ports operating as(defined as) PSE ports (e.g., 90 W or other power level ports). In thisexample, the network device 45 includes an FMP TX port 52 d, which maybe used to transmit FMP to a device or transmit excess power back toutility.

A second network device 46 (middle device in FIG. 4 ) is configured withbi-directional PoE ports 52 a, PSE PoE ports 52 b, and PD PoE ports 52c. The bi-directional PoE ports 52 a are shown coupled to the battery orenergy storage system 53.

A third network device 48 (bottom device in FIG. 4 ) is configured formicro-grid input and comprises a plurality of the PD PoE ports 52 c. Thethird network device 48 may comprise, for example, a low power switchconfigured to pass basic commands, data, and other information to aprimary network device (e.g., network device 46 coupled to the bus 49).In this example, the third network device 48 has a plurality of PVdevices 54 (e.g., thin solar panel or film with connected electronics)coupled to the PD PoE ports 52 c for transmitting power to the networkdevice 48. The network device 48 may be referred to as a PD aggregatorand may combine power received from the energy resource devices 54 atthe PD PoE ports 52 c and transfer the combined power over the power bus49 to another network device (e.g., network device 45) comprising thePSE PoE ports 52 b.

A side view of the PV device 54 is shown in FIG. 4 . The PV device mayinclude, a thin solar panel or film 54 a (e.g., transparent,semi-transparent, opaque, or sun blocking) configured for mounting on awindow, or any other device comprising photovoltaic cells operable toconvert light into electricity. The solar panel 54 a may be connected toa PoE device comprising a PSE port 54 b or a bi-directional PoE port 54c. For example, a solar window blind may receive power for use inrolling up or down the window blind and transmit power generated whenthe sun is out to the network device 48. Thus, one or more of the PD PoEports 52 c may be configured as a bi-directional PoE port 52 a operableto transmit power to the PV device 54 or receive power from the PVdevice.

It is to be understood that the system shown in FIG. 4 is only anexample and the bi-directional PoE system may include any number ofnetwork devices (e.g., switches, routers, switch/routers) comprising anynumber, type, or combination of ports (PD PoE, PSE PoE, bi-directionalPoE, FMP TX, FMP RX, FMP TX/RX) in any arrangement. One or more of thenetwork devices 45, 46, 48 may receive utility power or FMP, aspreviously described with respect to FIG. 3 . The network devices may bemounted in a rack, cabinet, or ceiling, for example.

FIG. 5 is a simplified block diagram illustrating an overview ofbi-directional PoE operation, in accordance with one embodiment. A frontend power distribution system 55 provides power to one or morebi-directional PoE ports 56. Each port comprises a PD circuit 57 a and aPSE circuit 57 b coupled to a controller 58 operable to detect powerdirection and enable PD or PSE operation. The controller 58 transmits anenable (EN) signal to enable PD operation at PD circuit 57 a or PSEoperation at PSE circuit 57 b. The port will transmit power to a load orreceive power from a source (load/source 59). In one or moreembodiments, the system incorporates a PD block 57 a and a PSE block 57b with FET (Field Effect Transistor) bridging (described below withrespect to FIGS. 10 and 11 ) to enable a negotiated direction of power(transmitting or receiving). An enable pin may be provided in acontroller chip along with a state diagram set identifying basic PoE PSEand PD direction specific negotiations.

FIG. 6 is a block diagram of a bi-directional PoE network device 60(e.g., switch or other network device), in accordance with oneembodiment. In this example, two PSUs (Power Supply Units) 61 and an FMPunit 62 are coupled to a bi-directional PoE port 63, which supports PSEor PD operation, a PSE PoE port 64, and a PD PoE port 65. The PSU 61 mayreceive utility power or PSU input power from the FMP module (poweradapter) 43 described above with respect to FIG. 3 . In this example,the components (ports 63, 64, 65, PSU 61 and FMP unit 62) are coupled toan internal system 77 providing regulated and isolated 54 VDCdistribution (or any voltage up to 60 VDC), for example. The PSUs 61receive utility power (e.g., AC, DC, or FMP input) at block 66, whichpasses through isolation circuit 67 to provide regulated output power atblock 68. The FMP unit 62 receives power from an isolation circuit 69,which is transmitted to a power converter operable to convert 54 VDC (orother regulated power) to HVDC (high voltage DC) at block 70. FMP istransmitted at block 71.

The network device 60 includes a POL (Point-of-Load) 72 coupled to theinternal system 77 via an isolation circuit 73 and regulated power block74. The POL 72 provides power over multiple rails to one or moreintegrated circuits (e.g., switching/routing ASIC (Application SpecificIntegrated Circuit) 75). The ASIC 75 is coupled to the bi-directionalPoE port 63 through a PSE/PD power controller 76 operable to enable PSEor PD operation, as previously described with respect to FIG. 5 . Theports 63, 64, 65 receive regulated and isolated power from the internalpower distribution system and data from the ASIC 75. As previouslynoted, the network device 60 may include any number or combination ofbi-directional, PD, PSE, or FMP ports. Each PoE port comprises a PoEconnector (e.g., RJ-45 or other suitable connector) for transmitting PoE(bi-directional PoE port 63, PSE PoE port 64) or receiving PoE(bi-directional PoE port 63, PD port 65). Each port also comprises a PSEcircuit 78 a, PD circuit 78 b, or both PSE and PD circuits.

FIG. 7 illustrates an example of a single pair multi-drop (SPMD)bi-directional system, in accordance with one embodiment. In thisexample, a PSE port 90 transmits power and data over a cable 91 to aplurality of powered devices 92 (PD₁, PD₂, PD₃, PD₄, . . . PD_(x)). SPMDprovides PSE simplification as voltage regulation is done at the PD.Power per segment may be more restricted due to a larger current on thesingle wire pair. The PSE port 90 and PDs 92 are configured forbi-directional PoE operation.

FIG. 8 is a simplified electrical schematic of the powered device 92, inaccordance with one embodiment. In this example, a voltage conditioner93 is coupled to a solar device 94 and senses polarity and adjusts asneeded. A PD IC (Integrated Circuit) 95 is coupled to a load and a diodebridge 96. The voltage conditioner 93 may also sense voltage andregulate voltage at power in/out (A/B). The voltage conditioner 93 mayinclude PSE functionality so that it can disable PD operation at the PDIC 95 to prevent self-discovery.

In order to account for different cable lengths connecting thebi-directional PoE ports to the connected devices, which will result indifferent voltages at the PSE (for reverse power system), voltageconditioner 93 is inserted into a switch 99 with bi-directional ports,as shown in FIG. 9 . In this example, V1≠V2≠V3≠V4 due to the differentcable lengths L1, L2, L3, and L4 connecting bi-directional PDs 92 (PD₁,PD₂, PD₃, PD₄), respectively to the switch. The voltage conditioners 93are coupled to the internal system regulated and isolated distributionsystem 97 through voltage line (Vout) 98 a and current sense line 98 b.

FIGS. 10 and 11 illustrate PD and PSE circuits for the bi-directionalPoE port, in accordance with one embodiment. For simplification andclarity, the circuits are shown separately in FIGS. 10 and 11 , however,it is to be understood that that the PD and PSE circuits are bothlocated at the bi-directional PoE port and are connected to the same setof transformers 103 coupled to the twisted pairs 102 of the cable.

FIG. 10 is an electrical schematic of a PD circuit for bi-directionalPoE, generally indicated at 100. In this example, a connector (e.g.,RJ-45 connector) is coupled to a cable comprising four twisted pairs102. The PD circuit 100 includes two bridge rectifiers 105 coupled to aPD chip (PD IC) 104 comprising an N-FET. The PD chip 104 is coupled to aPD load 108 and PD operation is enabled at the PD chip with a PD enablesignal. The PD chip 104 provides detection, presents classification, andcontrols the hot swap FET. The circuit also includes a regulator 106.

FIG. 11 is an electrical schematic of a PSE circuit for bi-directionalPoE, generally indicated at 110. PSE enable is provided by a controlsignal at a PSE controller 112. In one or more embodiments, an enablesignal is used to avoid problems with combining both PD and PSE to thesame eight pins in which case the PSE may self-detect. The circuit 110includes two P-FETs 114 and an N-FET 115.

The port includes center-tap transformers 103 that operate in a phantompower mode to either separate data from power when combined data andpower are received (for PD operation shown in FIG. 10 ) or combine datawith power and then transmit the combined data and power (for PSEoperation shown in FIG. 11 ). Combined data and power is carried overthe twisted pair conductors 102 in the Ethernet cable. The PoE power iscarried bi-directionally on the same connector and pins at the port andalong the same pairs of twisted wires in the cable.

FIG. 12 illustrates an example of a network device 120 (e.g., switch,router, and the like) that may implement one or more embodimentsdescribed herein. In one or more embodiments, the network device 120 isa programmable machine that may be implemented in hardware, software, orany combination thereof. The network device 120 includes one or moreprocessor 122, memory 124, interface 126, and bi-directional PoEcontroller (power controller) 128.

Memory 124 may be a volatile memory or non-volatile storage, whichstores various applications, operating systems, modules, and data forexecution and use by the processor 122. The network device 120 mayinclude any number of memory components.

Logic may be encoded in one or more tangible media for execution by theprocessor 122. For example, the processor 122 may execute codes storedin a computer-readable medium such as memory. The computer-readablemedium may be, for example, electronic (e.g., RAM (random accessmemory), ROM (read-only memory), EPROM (erasable programmable read-onlymemory)), magnetic, optical (e.g., CD, DVD), electromagnetic,semiconductor technology, or any other suitable medium. In one or moreembodiments, logic may be encoded on one or more non-transitory computerreadable media for execution and when executed operable to perform thesteps described below with respect to FIGS. 13, 14, and 20 . The logicmay be in the form of software executed by the processor, digital signalprocessor instructions, or in the form of fixed logic in an integratedcircuit, for example. The network device 120 may include any number ofprocessors 122.

The network interface 126 may comprise any number of interfaces (linecards, ports, bi-directional PoE ports, PD ports, PSE ports) forreceiving power and data or transmitting power and data to other networkdevices.

The bi-directional PoE controller 128 may be used to detect powerdirection, negotiate PoE, and enable PD or PSE operation, for example.The controller 128 may also perform PSE operations including, forexample, PD detection and classification when the port is configured tooperate as a PSE port or perform PD operations including, for example,presenting to the PSE valid detection and classification signatures inresponse to the PSE operations. The controller 128 may selectivelyactivate (enable) the PD circuit shown in FIG. 10 or the PSE circuitshown in FIG. 11 . The controller 128 may also monitor local powerrelated parameters, current flows, or telemetry information, track powerflow direction, and initiate a role reversal at the bi-directional PoEport. The power flow direction may be changed, for example, if excesspower availability is identified at the PD.

It is to be understood that the network device 120 shown in FIG. 12 anddescribed above is only an example and that different configurations ofnetwork devices may be used. For example, the network device may furtherinclude any suitable combination of hardware, software, algorithms,processors, devices, components, or elements operable to facilitate thecapabilities described herein.

As previously described, the bi-directional PoE ports perform dynamicswitching between PSE and PD roles of the ports at opposite ends of acable so that power can flow bi-directionally. FIGS. 13 and 14 areflowcharts illustrating an overview of a process for PSE/PD and PD/PSErole reversal, in accordance with one embodiment. FIG. 13 describes aprocess in which the network device port starts out as a PSE (PSE mode)and switches to PD mode. FIG. 14 describes a process in which thenetwork device port starts out as a PD (PD mode) and switches to PSEmode.

Referring first to FIG. 13 , the bi-directional PoE port starts in PSEmode at step 130. The system waits for PoE standard negotiation at step131 and once PoE negotiation is complete, the PSE powers the PD (step132). If the PSE receives a request from the connected PD to become aPSE (step 133), the PSE will switch from a source (PSE mode) to a sink(PD mode) (step 134) and accept power (step 135) from the connecteddevice, which is now operating as a PSE. If there is a failure or theconnected device is no longer providing sufficient power (step 136), thedevice switches back to PSE mode (step 137) and powers the PD (step132).

Referring now to FIG. 14 , the bi-directional PoE port starts in PD mode(step 140). The port negotiates a power class (step 141) and receivespower from the PSE (step 142). If power is available to source at thedevice (step 143), the PD may send a request to the PSE to switch modes(step 144). Upon receiving approval to switch modes (step 145), thedevice negotiates available power to source and a power source class(e.g., 15 W, 30 W, 45 W, 60 W, 90 W, 150 W, 200 W, 350 W, or any othersuitable power level) (step 146). The device switches from PD mode toPSE mode (step 147) and delivers power to the connected device (step148). If there is a failure or the device no longer has available powerto source (or available power drops off) (step 149), the device switchesback to PD mode (step 150) and receives power from the PSE (step 142).

It is to be understood that the processes shown in FIGS. 13 and 14 areonly examples and steps may be added, deleted, modified, reordered, orcombined, without departing from the scope of the embodiments.

FIG. 15 illustrates power management in a bi-directional PoE systemoperable to receive power from utility power, solar energy, or batteryenergy. In a graph shown in FIG. 15 , solar power varies throughout theday as illustrated at trace 151. In this example, utility power provides80% of available power, as shown at 154, and battery power provides theremaining 20% of available power, as shown at 152. It is to beunderstood that the power sources described in FIGS. 15-19 are onlyexamples and additional power sources or different power sources may beused, without departing from the scope of the embodiments. Based on theavailable power and the number of active ports (active PSE ports), theports may shed power, limit power, or add power to the system. In one ormore embodiments, power may be shared among ports using an isolateddistribution bus, as previously described.

FIGS. 16-18 illustrate different examples of power availability andusage. In a first example, shown in FIG. 16 , utility power provides 80%of the maximum port power as indicated at 164. The available batterypower shown at 162 is based on a battery in fully charged state. Thesolar power 161 and battery power 162 may be reserved for port usage orpushed into utility power.

In a second example shown in FIG. 17 , battery power 172 is reserved forbackup. 100% power is available for port use for at least part of theday using a combination of utility power 174 and solar power 171. Whenthe solar power exceeds the needed power, the extra power may be pushedinto utility. When the solar power drops off, power may be reduced atone or more ports.

In a third example shown in FIG. 18 , 100% of power is available fromutility 184 and battery 182 and may be dynamically applied. Extra solarpower 181 at peak solar time may be used to charge the battery or pushedinto utility power.

In a fourth example shown in FIG. 19 , only solar power 191 and batterypower 192 are used, with no utility power. Power may need to be reducedat one or more ports when available power is less than 100%.

Various algorithms may be implemented to determine how to use availablepower and how to allocate power to the active ports. The system may beconfigured to shed power (turn off one or more ports, reduce power atone or more ports), limit power, reserve power, add excess power back toutility, or any combination thereof. The controller may use any type ofalgorithm (e.g., default, user defined) to determine how to allocateavailable power to active ports. The controller may take into accountthe time of day, weather conditions (cloudy, sunny), battery chargestatus, priority of one or more network devices or ports, or any otherparameters or variables in allocating power to the active ports.Connected devices may collect data that provides information such asenergy usage or building occupancy, which may be used in systemanalytics. The system may also include smart services with analytics(e.g., IoT enabled smart control applications at endpoint devices) withany number of sensors or type of monitoring. The power controller maycommunicate with one or more devices using any suitable power managementcommunication protocol, including for example, LLDP (Link Layer DataProtocol), which may also be used to signal role reversal of thebi-directional PoE ports.

FIG. 20 illustrates an overview of a process in which available utilitypower, solar power, and battery power is identified and allocated forany number of ports. Power allocation may be based on any number ofparameters including, time of day, power availability, port priorities,etc. Available power from a plurality of power sources comprising autility power source, a solar power source, and a battery power sourceis identified at step 200. Active ports in the bi-directional PoE systemare identified (e.g., PSE ports or bi-directional ports operating asPSE) (step 202). A portion (0-100%) of each power source may be selectedto power the ports or for another use (e.g., extra solar power pushedinto utility power, extra power used to charge battery) (step 204). Acontroller allocates power from one or more of the power sources topower the active ports (step 206). Power may be reduced at one or moreports if available power is less than needed at all ports operating atfull capacity. This may include turning off one or more ports orlimiting power at one or more ports. This process may be continuallyupdated as power levels change (e.g., available solar power variesthroughout the day or changing weather conditions, battery charged) andadjusted to meet varying needs at the ports. For example, one or morepowered devices may have available power to put back into thebi-directional PoE system, thereby reducing system power needs. Thepower identification and allocation may be updated periodically or uponsensing a change in power usage or availability.

It is to be understood that the process shown in FIG. 20 is only anexample and steps may be modified or added without departing from thescope of the embodiments. Also, any combination of power sources may beused (e.g., utility, battery, solar, wind) to power any number or typeof ports.

Although the method and apparatus have been described in accordance withthe embodiments shown, one of ordinary skill in the art will readilyrecognize that there could be variations made without departing from thescope of the embodiments. Accordingly, it is intended that all mattercontained in the above description and shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:
 1. A system comprising: a plurality of networkdevices comprising a plurality of ports; a common shared power busconnecting said plurality of network devices, wherein power is sharedbetween said plurality of network devices over the common shared powerbus; and a controller for identifying available power and allocatingpower to said plurality of ports; wherein said plurality of portscomprises: a plurality of PSE (Power Sourcing Equipment) PoE (Power overEthernet) ports each operable to transmit power to a device connected toone of the PSE PoE ports; a plurality of PD (Powered Device) PoE portseach operable to receive power from a device connected to one of the PDPoE ports; and a plurality of bi-directional PoE ports each configurableto operate as a PSE PoE port to transmit power to a device connected toone of the bi-directional PoE ports or as a PD PoE port to receive powerfrom the connected device.
 2. The system of claim 1 wherein the deviceconnected to one of the bi-directional PoE ports comprises a solardevice.
 3. The system of claim 1 wherein the device connected to one ofthe bi-directional PoE ports comprises a rechargeable battery.
 4. Thesystem of claim 1 wherein a plurality of photovoltaic devices areconnected to a group of the PD PoE ports.
 5. The system of claim 1,wherein the controller is located at one of the plurality of networkdevices and is a system power controller that identifies available powerin the system and allocates the available power to the plurality ofports of the plurality of network devices.
 6. The system of claim 1,wherein at least one of the network devices receives utility power, thedevice connected to one of the bi-directional PoE ports comprises arechargeable battery, and the device connected to one of the PD PoEports or one of the bi-directional PoE ports comprises a solar device,and wherein the controller is configured to identify available utilitypower, available battery power, and available solar power and determinea portion of each of the available utility power, the available batterypower, and the available solar power to use for powering the pluralityof ports.
 7. The system of claim 1, wherein said plurality of portsfurther comprises a fault managed power port configured to transmitfault managed power to one of the network devices.
 8. The system ofclaim 7, wherein the fault managed power port is further configured totransmit excess power back into a utility power source.
 9. The system ofclaim 1, wherein the common shared power bus couples together theplurality of network devices and is configured for transmitting power ina voltage range of 54 VDC (Volts Direct Current) to 60 VDC.
 10. Anapparatus comprising: a plurality of bi-directional PoE (Power overEthernet) ports each configurable to operate as a PSE (Power SourcingEquipment) PoE port to transmit power to a device connected to one ofthe bi-directional PoE ports or as a PD (Powered Device) PoE port toreceive power from the device; a power supply unit; and a fault managedpower module having a fault managed power port for receiving faultmanaged power on an Ethernet cable, converting the fault managed powerto a power supply input power, and transmitting the power supply inputpower to the power supply unit, wherein the fault managed power moduleis aligned for connection with the power supply unit.
 11. The apparatusof claim 10, wherein the fault managed power comprises DC (DirectCurrent) pulse power and wherein the power supply unit is a removablemodule configured to provide the power supply input power to theapparatus and wherein the power supply input power is provided by thefault managed power module to the power supply unit.
 12. The apparatusof claim 10 further comprising at least one PD PoE port or PSE PoE port.13. The apparatus of claim 10 wherein each of said plurality ofbi-directional PoE ports comprises a PD circuit and a PSE circuitconnected to a same set of transformers coupled to twisted pairs of anEthernet cable, the PSE circuit comprising a PSE controller with anenable signal input for use in switching between PD and PSE operation.14. The apparatus of claim 10 wherein the device connected to one of thebi-directional PoE ports comprises a solar device operable to receivepower when the bi-directional PoE port operates as the PSE PoE port ortransmit power when the bi-directional PoE port operates as the PD PoEport.
 15. The apparatus of claim 10 wherein at least one of thebi-directional PoE ports is operable to transmit or receive power from aplurality of devices connected to the bi-directional PoE port on asingle pair cable in a multi-drop arrangement.
 16. The apparatus ofclaim 15 wherein each of said plurality of devices comprises a voltageconditioner.
 17. The apparatus of claim 10 wherein each of saidplurality of bi-directional PoE ports comprises a voltage conditioner toaccount for different cable lengths connecting the bi-directional PoEports to the connected devices.
 18. The apparatus of claim 10 whereinthe device connected to one of the bi-directional PoE ports comprises abattery operable to receive power when the bi-directional PoE portoperates as the PSE PoE port or transmit power when the bi-directionalPoE port operates as the PD PoE port.
 19. A method comprising:identifying available power from a plurality of power sources comprisinga utility power source, a solar power source, and a battery powersource; identifying active ports in a bi-directional Power over Ethernet(PoE) system; and allocating power from one or more of said plurality ofpower sources to power the active ports by determining a portion toselect of the plurality of power sources to power the active ports or tocharge another one of the plurality of power sources.
 20. The method ofclaim 19 wherein allocating power further comprises allocating power tocharge the battery power source or add to the utility power source. 21.The method of claim 19 further comprising transmitting extra battery orsolar power back into the utility power source.
 22. The method of claim19 further comprising reducing power at one or more of the active portsbased on said available power.
 23. The method of claim 22 whereinreducing power comprises turning off one or more of the active ports.24. The method of claim 22 wherein reducing power comprises limitingpower at one or more of the active ports.
 25. The method of claim 19further comprising reserving the battery power source for backup power.26. A system comprising: a plurality of energy resource devices; anetwork device comprising a plurality of PD (Powered Device) PoE (Powerover Ethernet) ports operable to receive power from the energy resourcedevices connected to the PD PoE ports; and a common shared power bus forreceiving power from the network device and transmitting power to atleast one other network device comprising a plurality of PSE (PowerSourcing Equipment) PoE ports for transmitting power to powered devices.27. The system of claim 26 wherein the PD PoE ports comprisebi-directional PoE ports operable to transmit power to the energyresource devices or receive power from the energy resource devices. 28.The system of claim 27 wherein the energy resource devices comprise oneor more photovoltaic devices or rechargeable battery devices eachoperable to switch between a first mode configured to receive power fromone of the bi-directional PoE ports and a second mode operable totransmit power to one of the bi-directional PoE ports.
 29. The system ofclaim 26 wherein the energy resource devices comprise a plurality offlexible solar panels.
 30. The system of claim 26 wherein the energyresource devices comprise a plurality of solar window blinds.
 31. Thesystem of claim 26 wherein the energy resource devices comprisesemi-transparent solar films configured for mounting on windows.
 32. Thesystem of claim 26 wherein the network device comprises a powered deviceaggregator for combining power received at the PD PoE ports from theenergy resource devices.